(1) Field of the Invention
The present invention relates to a liquid crystal display device, and in particular, to a semi-transmission type liquid crystal display device into which a phase difference film is incorporated on the color filter substrate side.
(2) Related Art Statement
Semi-transmission type liquid crystal display devices are known which have a transmission portion and a reflection portion within one subpixel and are used as a display for a portable apparatus (see the following Patent Document 1).
FIG. 7 is a cross sectional diagram schematically showing a main portion of the configuration of one subpixel in a conventional semi-transmission type liquid crystal display device having an IPS system, which is the semi-transmission type liquid crystal display device having an IPS system shown in FIG. 6 of the following Patent Document 1.
In the figure, SUB1 is a first substrate (which is also referred to as TFT substrate), and a thin film transistor for forming an active element, a facing electrode (CT), a reflection layer (RAL), an interlayer insulating film (PAS), a pixel electrode (PX) and an orientation film (AL1) are formed on the first substrate (SUB1). Here, in FIG. 7, interlayer insulating films other than PAS which are formed on the facing electrode (CT) side are omitted.
In addition, SUB2 is a second substrate (which is also referred to as color filter substrate), and a light shielding film (BM), an incorporated phase difference film (RET), a color filter (CF), a flattened film (OC), a step forming layer (MR) and an orientation film (AL2) are formed on the second substrate (SUB2).
Here, polarization plates (POL1, POL2) are formed on the outside of the first substrate (SUB1) and the second substrate (SUB2), respectively. In addition, in the semi-transmission type liquid crystal display device shown in FIG. 7, the main surface side of the second substrate (SUB2) is a viewed side.
In the semi-transmission type liquid crystal display device shown in FIG. 7, light is blocked in the periphery of one subpixel region by the light blocking film (BM) formed on the second substrate (SUB2) side, and therefore, in the semi-transmission type liquid crystal display device shown in FIG. 7, the region (PT) which functions as a substantial one subpixel region is the opening of the light blocking film (BM). This region (PT) is divided into a transmission portion 30 and a reflection portion 31, and the step forming layer (MR), the incorporated phase difference film (RET) and the reflection layer (RAL) are formed in the reflection portion 31.
Here, the prior art documents relating to the present invention include the following.
[Patent Document 1] Japanese Unexamined Patent Publication 2006-98623